1. Field of the Invention
The present invention relates to an air-conditioning system or a refrigerant loop with a variable-stroke compressor, wherein the stroke of the compressor is regulated by the inflow of refrigerant medium from a pressure outlet chamber into a drive chamber and/or by the discharge of refrigerant medium from the drive chamber into a suction pressure chamber.
2. Description of the Related Art
Conventional air-conditioning systems of the type described above include a valve with an internal mechanical suction pressure-regulating device. This suction pressure-regulating device may in some cases be of a type where a control target value can be set externally through a magnet.
Other conventional air-conditioning systems have a four- or two-way valve, which either pressurizes or depressurizes the drive chamber. These conventional air-conditioning systems suffer from the drawbacks that the valves with internal suction-pressure regulators can only regulate the suction pressure, that these valves have a considerable hysteresis that is detrimental to their regulating performance, and that they offer no possibility of effectively controlling lubricant circulation. Air-conditioning systems with four- or two-way valves for regulating the compressor do not allow the outflow and inflow to be controlled independently at the same time.